1. Field of the Invention
The present invention relates generally to DC batteries and, more particularly, to a method of using partially charged DC batteries in conjunction with metal blanks to extend the useful life of batteries used by a battery-powered apparatus.
2. Description of Related Art
Commonly, many devices such as portable radios, flashlights, or toys use DC batteries as power sources. A common problem has existed since the advent of these batteries in that dry cell batteries have a limited operating life span and are usually not rechargeable. Once the energy in a conventional DC battery has been expended below a predetermined voltage level, its usefulness ceases and the battery must be discarded and replaced.
Research continues to be conducted to develop batteries with extended life spans. This research has led to the relatively recent development of the alkaline battery. However this battery will also eventually lose its energy and cease to operate. Therefore, problems associated with the use of conventional DC dry cell batteries still exist. In particular, battery-powered devices will not operate once the voltage of a battery power source falls below a predetermined, threshold voltage level required for a particular battery-powered device.
Therefore a need still exists for a device which may extend the life of a DC battery used as a power source. Further, a need exists to reduce energy waste caused by discarded DC batteries in a weakened energy state with residual DC energy. A discussion of related art follows.
U.S. Pat. No. 5,277,993, issued Jan. 11, 1994 describes a device which is capable of replacing one or more of a plurality of DC batteries used as a power source and capable of extending the life of the batteries used. However, this invention does not disclose a method by which batteries may be used in a weakened state.
U.S. Pat. No. 3,201,742, issued Aug. 17, 1965, describes an electric connector device for replacing an exhausted dry cell battery with a "power pack." According to the described invention, battery cells are replaced by an improved connector and any remaining battery spaces are filled in by dummy batteries. Although this patent discloses the use of dummy cells for providing connectivity, this patent does not disclose replacing these dummy cells with weakened batteries to extend the useful life of a battery. Instead U.S. Pat. No. 3,201,742 discloses use of a combination transformer and rectifier connected to a conventional electric outlet to provide a power source.
Other patents of note include, U.S. Pat. No. 1,464,573, issued Aug. 14, 1923 to Heise et al.; U.S. Pat. No. 2,886,623, issued May 12, 1959 to Lehr; U.S. Pat. No. 2,938,111, issued May 24, 1960 to Keilman; U.S. Pat. No. 3,486,944, issued Dec. 30, 1969 to O'Donnell; U.S. Pat. No. 4,962,347, issued Oct. 9, 1990 to Burroughs et al.; and U.S. Pat. No. 5,197,796, issued Mar. 30, 1993 to Moore; all show battery operated devices capable of holding or using temporary battery substitutions.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.